CMOSTEK CMT2250A, Configuration Manuallines

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3.3.1 Application Example 1: Fixed Duty
Table 4. Fixed Duty Configurations
Options Value
Sleep Time 5,000 ms
Rx Time 400 ms
Rx Time Ext NA
Wake-On Radio Off
Preamble NA
Rx Early Exit Off
Valid Reception 1 packet
The sleep and receive time is fixed to 5,000 ms and 400 ms, respectively.
The Xtal Stabilizing Time is set to 310 us.
SLEEP SLEEP RX
(400 ms)
XTAL
(310 us)
SLEEP
(5,000 ms)
TUNE
(300 us)
XTAL
(310 us)
TUNE
(300 us)
RX
(400 ms)
time
Figure 11. Fixed Duty Operation
After a successful power up, the device enters the SLEEP state. When it reaches the sleep timeout of 5,000 ms, it switches to
XTAL state to wait for the crystal to get stable. Subsequently it takes about 300 us to tune the frequency synthesizer to the
desired frequency. Once the frequency synthesizer is locked, the device starts receiving. When the Rx timer is timeout at 400 ms,
the device switches back to the SLEEP state and repeat the same cycle continuously until it is powered down.
In this example, the non-receive time is 5,000 + 0.31 + 0.3 = 5,000.61 ms. The receive time is 400 ms. Therefore, according to
the principle introduced in the “Precise Configuration”, the Tx burst time must be longer than 5,400.61 ms, and 2 data packets
must appear during the RX state for safety.
3.3.2 Application Example 2: Wake on Preamble
Table 5. Wake on Preamble Configurations
Options Value
Sleep Time 800 ms
Rx Time 20 ms
Rx Time Ext 200 ms
Wake-On Radio On
Preamble 16-symbol
Rx Early Exit Off
Valid Reception 1 packet
The wake-on radio function provides a powerful scheme to save the power. In this example, the receive time is set to 20 ms
which is much shorter than the packet length. The sleep time is 800 ms.
When there is no effective signal received, the radio acts like the one introduced in the Application Example 1. Because the Rx
time is much shorter, more power is saved.